This invention relates to hydraulically transported capsules which contain goods to be transported and are moved through a tubular passageway through which a liquid, such as water, flows, for hydraulically transporting the goods contained in the capsules.
Heretofore, the capsules of the type described usually has had a spherical or cylindrical shape.
When capsules of the cylindrical shape are moved through the tubular passageway by the force of a liquid, such as water, the capsules move in rolling movement along the upper portion or the lower portion of the inner wall surface of the tubular passageway depending on the specific gravity of the capsules. Thus, relatively little resistance is offered to the movement of capsules by the tubular passageway and the capsules can be moved smoothly without any trouble.
However, the capsules of the spherical shape have the disadvantages of requiring a complex structural arrangement for mounting a cover member on each capsule, and of being small in the capacity for containing goods to be transported. Because of these disadvantages of the capsules of the spherical shape, it has hitherto been customary to use capsules of the cylindrical shape as capsules of the type adapted for hydraulically transporting goods as aforementioned. When the capsules of the cylindrical shape are used for the stated purpose, the capsules move in sliding movement along the inner wall surface of the tubular passageway depending on its specific gravity while repeatedly colliding with the preceding capsule or the next following capsule. Thus, the capsules of the cylindrical shape are subjected to a high resistance offered by the tubular passageway, and require high power as a source of force for moving the same.
U.S. Pat. No. 3,633,976 discloses means for obviating these disadvantages. The capsule disclosed in said U.S. patent has a collar mounted at the forward end thereof, so that the collar is brought at its outer periphery into contact with the inner wall surface of the tubular passageway so as to slidably support the capsule when the capsule is moved by the force of flowing water.
However, the capsule of the type disclosed in the U.S. patent referred to above is not without a disadvantage. If the collar has on its periphery an acute-angled step, the step may be engaged with or hooked against a step on a joint of pipes forming the tubular passageway or on a junction of the tubular passageway, thereby causing jamming of the capsules which might result in blocking of the tubular passageway through which the capsules are moved.
Moreover, since the capsule of the aforesaid U.S. patent has an entirely rigid structure, there is the hazard of an end portion of the capsule being damaged or undergoing deformation in the event that there is a change in the rate of movement of the capsule, particularly when the capsule is subjected to high forces of inertia in starting or stopping. If the capsule is severely damaged or deformed, the cover member of the capsule would be dislodged from its position on the capsule and the goods transported by the capsule would be scattered in the tubular passageway, thereby obstructing the movement of other capsules through the tubular passageway and rendering the transportation system not available for further use. Thus, the capsule of the type described in the aforementioned U.S. patent may make it impossible to carry out transportation of goods with safety by using the hydraulic force.